As Gmail passes 1 billion downloads, we take a look at what that actually means

That's an easy answer, actually, but we'll go one further and explain exactly what you're looking at when you see an app's download numbers in the Google Play listing. There are downloads, and then there are downloads. There are installations. There are uninstalls. There are folks who use the same app on more than one device. Gmail, for instance, is on every device that has official access to Google Play. Same for Google Maps. And other apps.

So what counts as a download? And what do all the numbers mean when you're trying to judge whether you want to install an app?

Developers get to see way more than most of us

What you see on Google Play is the number of times an app has ever been downloaded. Forever-ever.

First, let's think of two kinds of users. "Developers" — that'd be folks who have a developer account with Google Play and can upload applications — and then "everyone else." Developers have quite a few tools at their disposal for app statistics. We'll get into those in a minute.

If you're not a developer, you really can only see one number one number for an app: the "downloads" listed in Google Play. And even then, you don't see a specific number listed. What you get is a range of downloads — say, 10,000 to 50,000. Or 100,000 to 500,000. (Gmail is currently in the 1,000,000,000 to 5,000,000,000 range. So it has between 1 billion and 5 billion downloads.)

But there's a catch. Or two, really.

Total installs versus current installs

(No, that's not the current Android Central app. But it does show you what developers get to see.)

"Regular users" get to see a very rough estimate of how many times and applications has been installed. But there's another catch. That rough estimate you see in Google Play is "total installs by users," and not necessarily an accurate count of how many people are actually using the app. Developers see a second number in their Developer Console alongside the total installs. That number is "current installs by device." And chances are the two numbers don't match up.

A more important number for developers might be the number of 'current' installations. They get to see it; the public doesn't.

Let's put it this way: Say I've made an app, and it's been installed by 10,000 total users. That'd put the app in the 10,000 to 50,000 category for public-facing purposes, even though it's on the low end of that scale. As a developer, I'm fine with that ambiguity. I'd love for folks to think my app actually has more downloads than it does.

But uninstalls happen. So it's possible our app with 10,000 total users actually has far fewer current users. There's no real way of knowing exactly what the current/total install ratio is without being the developer. I could have 10,000 total installs but only 2,000 current installs — a 20 percent keep rate. Not nearly as exciting.

What counts in the "total installs?" Google says it's "the number of unique users who have ever installed this app. We only count one install regardless of how many different devices they installed it on. It includes the users who have later uninstalled the app."

Current installs by user is marked as "the number of users who have the app currently installed on at least one active device." That one's simple enough.

Reports, reports and more reports ...

(Also not statistics for our current app.)

Developers actually have a number of other tools at their disposal for tracking how their apps are doing. When you first log in to the Developer Console, you see current installs by device next to total installs by users. So you see how many devices your app is on versus how many users have ever installed it. Once you drill into your app statistics, you get even more options. Here's the full list:

Current installs by device.

Daily installs by device.

Daily uninstalls by device.

Daily upgrades by device (this is the number of devices that updated from an older version of your app).

Current installs by user.

Total installs by user.

Daily installs by user.

Daily uninstalls by user.

So we can see how many users download our app. And how many devices our app is on. And how many uninstalls we see, both per device and by user.

Developers have a lot of tools at their disposal. Those browsing Google Play are left to guess a bit more.

And that's just download numbers. Google also tells us what version of Android users are running. (For context, 50 percent of folks using the Android Central App are on Android 4.4. We can get rough looks at which devices are being used. (Though that's a bit of a crapshoot as many don't properly report themselves.) We can see what country users are in. We can see what languages they default to. We can see how many users are on the older versions of our app. Or what mobile operator they're using.

And if you're a regular user, just remember this: The download numbers you see in Google Play are total user installs. That is, how many users have ever installed any version of the app. It's not an accurate look at how many are actually using it.

Reader comments

Ask AC: How many installs does an app really have?

So in the case of Gmail, has there really been at least 1 billion unique accounts that have downloaded and installed the Gmail app or is that number bloated by the fact that it is included with pretty much every Android device even if the user never uses the Gmail app?

I'm actually confused about when pre-installed apps get counted, and it is unclear from the article. For example, for all the HTC apps they used to approximate the number of M8 users, are they immediately counted when they log into the phone with their gmail account info? Or do they need to interface with the Play store before it counts? And you can theoretically use an android device without a Google account, so does it not count you then?

I actually think he has a valid question. The article didn't mention whether preloaded apps are counted. Though I would presume when those preloaded apps are updated (Gmail update) that install is probably counted for the first time. And I'd guess this would be the case even if the user never opened Gmail.

Once you log into your Google account, any pre-installed apps will be linked to your account on the Play Store. This is 1 billion unique user accounts, but that doesn't separate people who have multiple g-mail accounts like most of us developers do.

Now if we could have an article on how to become a developer or create your own app. I'm curious what the prerequisites are and how difficult it is. Do I have to take coding classes, are their any sites that help you build if you have a good idea, and so on.

Generally, if you don't already having some knowledge of coding, I'd recommend picking up a book on Android development or Java. One of those "Teach yourself in 24 hours" books can be a decent overview (assuming you don't actually try and do it in 24 hours).

Some people aren't good at learning from books. For that, you could probably look into taking a programming class or two at your local community college. There might even be some "independent" courses offered in your area.

It *really* depends where you are in your skill level for coding on exactly where you need to start.

If you've got some programming experience already, and you're just looking to learn Android, check out Google's Android Developer page.

Lots of examples and API documentation to get your started. Then search for some tutorials online, or pick up a book on Android development at your local book store. If you're familiar with Java, or at least the C syntax, it won't take a lot of effort to get started.

Download a copy of Eclipse with the ADT plugin, or the Android Development Studio, and write a few "Hello World" applications. Both can be downloaded from the Android Developer website. Personally, I recommend the Android Development Studio, but it can still be a bit buggy at times. You can even upload your apps to your phone and run them there, all for free. None of this developer license crap that Apple makes people go through just to tinker.

If you do get to a point where you want to upload an app to the Play Store, there is a one-time developer account "setup" fee of like $50 (I think, I haven't checked in a while).

Hopefully, that's enough to help you get started. I'd be happy to answer any other questions, if I can.

I call bullcrap on: "the number of unique users who have ever installed this app. We only count one install regardless of how many different devices they installed it on. It includes the users who have later uninstalled the app."

If that were the case, Google would be touting "we have 1 billion Gmail accounts!" and "we have 1 billion G+ accounts!!!" ...since /they say/ each install is a unique account. That's completely bogus, along with "X million Android devices activated each day!!!!" If I flash a new ROM on my exisiting phone, it shows up as a brand new phone in my device list.

Go take a look at the "Top Free" list in Google Play Store. Currently Gmail sits at #461. Why not #1 (currently Facebook)?

No,because if that was the case then the gmail app would never have "pinged" the store (because there is no gmail account and no way to connect to the store...)
So seems like the BS call by jaymoon is true

FB is ranked higher than gmail because it's rarely preloaded on a device like the GMail app, and those lists are ranked by current daily installs, not total installs. That way you don't see a list of 3+ year old apps that USED TO BE popular, but are largely forgotten now on the top lists. Also, you can use the GMail app to get your mail from other providers and not link it to a gmail account. Total gmail accounts should be found somewhere on Google's quarterly or yearly financial reports, as that is a metric used to calculate revenue per user.

I think you're making it a more complicated explanation than you have too. They are simply the total number of users (Google accounts) that have ever downloaded and installed an app OR signed in on a device with the app preinstalled. For example HTC Gallery shows up in my Google Play app listing once I signed in from the HTC One for the first time. Not the first time I downloaded an update.

A question I've wondered is how to deal with multiple installs of paid apps.
I use Pocket casts and think I paid for it (can't remember - perhaps it was a different pod at app that I no longer use). What stops me, apart from honesty, from installing it on my tablets and my spare phone. Or am I allowed to do this?

I've never come across an app that limits the number of installs, personally, but that doesn't mean it's impossible.

Generally, though, if you sign into a device with your Google account, then that device has access to every app you've ever purchased under that account. I have several apps (such as PocketCasts) installed on multiple devices that I own.

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